ts-guardian/lib/index.d.ts

Declarative, composable type guards

declare type BasicTypeMap = {
    any: any;
    boolean: boolean;
    bigint: bigint;
    function: Function;
    null: null;
    number: number;
    object: object;
    string: string;
    symbol: symbol;
    undefined: undefined;
    unknown: unknown;
};
declare type BasicTypeDef = keyof BasicTypeMap;
declare type BasicArrayTypeDef = `${BasicTypeDef}[]`;
declare type BasicOptionalTypeDef = `${Exclude<BasicTypeDef | BasicArrayTypeDef, 'undefined' | 'unknown' | 'any'>}?`;
declare type Literal = string | number | boolean;
declare type Instance = new (...args: any[]) => any;
interface ObjectTypeDef extends Record<PropertyKey, TypeDef> {
}
declare type TupleTypeDef = [] | (BasicTypeDef | BasicArrayTypeDef | BasicOptionalTypeDef | ObjectTypeDef | Guard<any>)[];
declare type TypeDef = BasicTypeDef | BasicArrayTypeDef | BasicOptionalTypeDef | ObjectTypeDef | TupleTypeDef | Guard<any>;
declare type BasicTypeDefType<T extends BasicTypeDef> = BasicTypeMap[T];
declare type StripArrayBrackets<T extends string> = T extends `${infer U}[]` ? U : never;
declare type StripOptionalMark<T extends string> = T extends `${infer U}?` ? U : never;
declare type TypeDefType<TTypeDef extends unknown> = TTypeDef extends Guard<infer V> ? V : TTypeDef extends BasicTypeDef ? BasicTypeDefType<TTypeDef> : TTypeDef extends BasicArrayTypeDef ? BasicTypeDefType<StripArrayBrackets<TTypeDef>>[] : TTypeDef extends BasicOptionalTypeDef ? (StripOptionalMark<TTypeDef> extends infer Stripped ? Stripped extends BasicArrayTypeDef ? BasicTypeDefType<StripArrayBrackets<Stripped>>[] : Stripped extends BasicTypeDef ? BasicTypeDefType<Stripped> : never : never) | undefined : TTypeDef extends ObjectTypeDef | TupleTypeDef ? {
    [key in keyof TTypeDef]: TypeDefType<TTypeDef[key]>;
} : never;
export declare type Guard<T extends unknown> = {
    (value: unknown): value is T;
    or: <U extends TypeDef>(t: U) => Guard<T | TypeDefType<U>>;
    and: <U extends TypeDef>(t: U) => Guard<T & TypeDefType<U>>;
    orArrayOf: <U extends TypeDef>(t: U) => Guard<T | TypeDefType<U>[]>;
    orRecordOf: <U extends TypeDef>(t: U) => Guard<T | Record<PropertyKey, TypeDefType<U>>>;
    orLiterally: <U extends Literal[]>(...t: U) => Guard<T | U[number]>;
    orInstanceOf: <U extends Instance>(t: U) => Guard<T | (U extends new (...args: any[]) => infer V ? V : never)>;
};
export declare type GuardType<T extends Guard<any>> = T extends (value: unknown) => value is infer U ? U : never;
export declare const is: <T extends TypeDef>(t: T) => Guard<TypeDefType<T>>;
export declare const isArrayOf: <T extends TypeDef>(t: T) => Guard<TypeDefType<T>[]>;
export declare const isRecordOf: <T extends TypeDef>(t: T) => Guard<Record<PropertyKey, TypeDefType<T>>>;
export declare const isLiterally: <T extends Literal[]>(...t: T) => Guard<T[number]>;
export declare const isInstanceOf: <T extends Instance>(t: T) => Guard<T extends new (...args: any[]) => infer V ? V : never>;
export declare const isOptional: <T extends TypeDef>(t: T) => Guard<TypeDefType<T> | undefined>;
export declare const isNullable: <T extends TypeDef>(t: T) => Guard<TypeDefType<T> | null>;
export declare const isNullish: <T extends TypeDef>(t: T) => Guard<TypeDefType<T> | null | undefined>;
/** @deprecated Use `is('boolean')` instead. */
export declare const isBoolean: Guard<boolean>;
/** @deprecated Use `is('bigint')` instead. */
export declare const isBigint: Guard<bigint>;
/** @deprecated Use `is('function')` instead. */
export declare const isFunction: Guard<Function>;
/** @deprecated Use `is('null')` instead. */
export declare const isNull: Guard<null>;
/** @deprecated Use `is('number')` instead. */
export declare const isNumber: Guard<number>;
/** @deprecated Use `is('string')` instead. */
export declare const isString: Guard<string>;
/** @deprecated Use `is('symbol')` instead. */
export declare const isSymbol: Guard<symbol>;
/** @deprecated Use `is('undefined')` instead. */
export declare const isUndefined: Guard<undefined>;
/** @deprecated Use `isNullable('boolean')` instead. */
export declare const isBooleanOrNull: Guard<boolean | null>;
/** @deprecated Use `isNullable('bigint')` instead. */
export declare const isBigintOrNull: Guard<bigint | null>;
/** @deprecated Use `isNullable('function')` instead. */
export declare const isFunctionOrNull: Guard<Function | null>;
/** @deprecated Use `isNullable('number')` instead. */
export declare const isNumberOrNull: Guard<number | null>;
/** @deprecated Use `isNullable('string')` instead. */
export declare const isStringOrNull: Guard<string | null>;
/** @deprecated Use `isNullable('symbol')` instead. */
export declare const isSymbolOrNull: Guard<symbol | null>;
/** @deprecated Use `is('boolean?')` instead. */
export declare const isBooleanOrUndefined: Guard<boolean | undefined>;
/** @deprecated Use `is('bigint?')` instead. */
export declare const isBigintOrUndefined: Guard<bigint | undefined>;
/** @deprecated Use `is('function?')` instead. */
export declare const isFunctionOrUndefined: Guard<Function | undefined>;
/** @deprecated Use `is('null?')` instead. */
export declare const isNullOrUndefined: Guard<null | undefined>;
/** @deprecated Use `is('number?')` instead. */
export declare const isNumberOrUndefined: Guard<number | undefined>;
/** @deprecated Use `is('string?')` instead. */
export declare const isStringOrUndefined: Guard<string | undefined>;
/** @deprecated Use `is('symbol?')` instead. */
export declare const isSymbolOrUndefined: Guard<symbol | undefined>;
declare type ParserReturn<T, TGuard extends Guard<any>> = T extends undefined ? GuardType<TGuard> | undefined : GuardType<TGuard> extends T ? T | undefined : never;
export declare const parserFor: <T extends unknown = undefined, TGuard extends Guard<any> = Guard<T>>(guard: TGuard) => (value: any) => ParserReturn<T, TGuard>;
export declare const requireThat: <T extends any>(value: any, guard: Guard<T>, errorMessage?: string) => asserts value is T;
/** @deprecated Use requireThat instead */
export declare const assertThat: <T extends unknown>(value: any, guard: Guard<T>, errorMessage?: string | undefined) => asserts value is T;
export {};